But even charities committed to rescuing unused food from restaurants and supermarkets draw the line at carting the daily mountain of bread headed for the tip.

''Bread is the cheapest commodity, it's so easy to keep churning out. For bakeries, if they want to make their shelves look full they have to keep making it,'' OzHarvest communications manager Louise Tran said.

''Our challenge is that if we collected that bread, we would only collect bread and you can't just expect to serve just bread for dinner.''

Research in Britain shows bread is the most wasted food, with Britons binning 1.2 billion, or 30 per cent, of bakery items and 2.6 billion slices of bread each year. The research by anti-waste organisation Wrap also found that the average British household throws away 240 kilograms of food each year.

No detailed research into the amount of bread wasted in Australia has been conducted.

But Australians throw away about 361 kilograms of food waste every year, the National Waste Report reveals. The Australia Institute found the average household throws out about $616 worth of food every year, with high-income-low-occupant households wasting the most food.

Colin Gray, chief executive of NSW Chamber of Fruit and Vegetables, says Australians are spoilt for choice when it comes to food. ''We produce more fruit and vegetables in this country than we can possibly consume,'' he said.

''What that means though is we're more discerning as a public. It means the small fruit, the large fruit, something with a bit of a mark is not what the consumer wants to buy.''

Food politics lecturer Gyorgy Scrinis, from the University of Melbourne, said public discourse too often takes a “blaming-the-consumer approach” to food waste.

“You go round in circles. Supermarkets blame consumers, saying that's what consumers want but on the other hand, supermarkets are also interpreting – selectively interpreting – what consumers want.”

Most programs focus on reducing food waste at the household level by educating consumers to use food more wisely or on redistributing food wasted at the end of the food chain, he said.

“But there's far less discussion about why food is being wasted throughout the supply chain,” Dr Scrinis said.

“There's deep-seated structural and cultural causes of food waste. We're tackling the cultural problems at the level of households but it really goes deeper than that.”

Few researchers focus on pre-consumer food waste. One 2011 study from researchers at Bond University, Queensland University of Technology and Griffith University, however, found that up to 30 per cent of the north Queensland banana crop was left at the farm gate – 78 per cent for cosmetic reasons.

Michael Silm, a grower with 40 years' experience in the fruit industry, said the specifications required to meet the standards of the major supermarkets made it “very difficult for growers”.

“They demand perfect fruit and if there's any small blemishes or anything that's on the skin, they won't accept it.”

Growers have to reject up to 30 per cent of fruit every harvest for purely cosmetic reasons so they can meet retailers' quality expectations, he added.

Scrinis says that Australia's supermarket duopoly means manufacturers are often left bearing the costs of the food the major retailers leave behind.

“Supermarkets have a lot of power in the supply chain,” Scrinis said.

“When they talk about reducing food waste they're talking about reducing what goes in their bins out the back, not what gets sent back to the manufacturer or what gets left at the farm gate.”

A Coles spokesperson said the retailer works “collaboratively with growers … by agreeing quality specs that cover size, colour, blemishes, speed to store, eating quality”. The company declined to provide figures on how much food waste is sent to landfill each year but its 2012 corporate sustainability report shows 7.5 per cent (7446 tonnes) of food waste was diverted from landfill to food charities and organic recycling last year. It sent 98,902 tonnes to landfill.

Woolworths has a target of zero food waste to landfill by 2015 but refused to comment on how close it was to achieving this target. According to the company's 2012 corporate sustainability report, Woolworths diverted 0.6 per cent (1980 tonnes) of its total waste disposal and recycling to food charities and 1.6 per cent (4733 tonnes) to composting and energy in 2012. Waste to landfill accounted for 37.8 per cent (111,800 tonnes) of waste disposal and recycling.

A company spokesperson said: “Woolworths has a number of measures in place to minimise food waste including stock ordering, stock management and markdowns and discounting to sell products before they reach the stage where they cannot be sold.”